Embodiments of the present invention generally relate to air delivery systems for static air cushion devices. More particularly, embodiments of the present invention relate to an air delivery system that intermittently operates an air pump or motor to deliver air to an inflatable cushion device while relatively continuously measuring a pressure corresponding to static air pressure within the inflatable cushion device.
The number of incidences of patients suffering from pressure ulcers reportedly continues to rise. For example, annually, approximately 2.5 million patients are treated in acute-care facilities for pressure ulcers. Dorner, B., Posthauer, M E & Thomas, D., The Role of Nutrition in Pressure Ulcer Prevention and Treatment: National Pressure Ulcer Advisory Panel White Paper, National Pressure Ulcer Advisory Panel (NPUAP) (2009), http://www.npuap.org/Nutrition%20White%20Paper%20Website%20Version.pdf. Caregivers therefore continue to seek to identify effective practices for addressing pressure ulcers, including steps for preventing and treating such ulcers.
Patients with pressure ulcers are often three times more likely to be discharged to a long-term care facility than those patients who do not suffer from pressure ulcers. Id. Further, pressure ulcers are more likely to occur among those over the age of 65 years. Thus, as the U.S. population aged 65 and older is expected to double within the next 25 years, the risk for, and subsequent prevalence of, pressure ulcers are expected to increase. Russo, C. A., Steiner, C., & Spector, W. Hospitalizations Related to Pressure Ulcers among Adults 18 Years and Older (2006) http://www.hcup-us.ahrq.gov. Additionally, people typically become frailer as they age. Because frailty and pressure ulcers share important risk factors such as, for example, incontinence, falls, delirium and functional decline, the anticipated increase in the size of the elderly population, and the associated frailness associated with the elderly, may add to the growing concern of pressure ulcer risk in the aging baby boomer population. Campbell, K., A New Model to Identify Shared Risk Factors for Pressure Ulcers and Frailty in Older Adults, Rehabilitation Nursing 34.6 at 242-47 (2009). Therefore, if proactive assessments, prevention, and/or early intervention are not implemented for the growing, high risk geriatric population, pressure ulcers could adversely impact the quality of health care delivered and the associated, and already worrisome, financial burdens. Sibbald, R., Krasner, D. & Woo, K L, Pressure Ulcer Staging Revisited: Superficial Skin Changes & Deep Pressure Ulcer Framework, Advances in Skin & Wound Care, 24.12 at 571-80 (2011). For example, the average cost associated with the treatment of Stage IV pressure ulcers has been reported as $129,248. Brem, H., Maggi, J., et al., High Cost of Stage IV Pressure Ulcers, The American Journal of Surgery, 200.4 at 473-77 (2010).
Since pressure ulcer prevention, early intervention, treatment and care has become a quality indicator used by federal/state agencies for regulatory oversight and litigation proceedings, avoidance of pressure ulcer related problems typically should occur by caregivers at multiple levels of care delivery. Vermette, S., Reeves, I. & Lemaire, J., Cost Effectiveness of an Air-inflated Static Overlay for Pressure Ulcer Prevention: A Randomize, Controlled Trial, Wounds, 24.8 at 207-14 (2012). For example, federal/financial fines for non-compliance with regulatory requirements associated with pressure ulcers may cost around $3,050 to $10,000 per day for development of avoidable Stage IV pressure ulcers. Brem, H., Maggi, J., et al., High Cost of Stage IV Pressure Ulcers, The American Journal of Surgery, 200.4 at 473-77 (2010). Further, the number of long-term legal cases related to pressure ulcers has increased from an average of 7 cases per year between 1984 and Aug. 31, 1999, to an average of 18 cases per year between September 1999 and 2010. Id. Further, recovery costs for parties in such cases also reportedly increased 403% from $3,359,259 in 1999 to $13,554,168 in 2002. Additionally, an apparent trend in verdicts being rendered in plaintiffs' favor may suggest that healthcare facilities are being held to a higher standard of care. Brem, H., Maggi, J., et al., High Cost of Stage IV Pressure Ulcers, The American Journal of Surgery, 200.4 at 473-77 (2010).
When the deep tissue injury component is considered in pressure ulcer staging, heel pressure ulcers are now first in occurrence. VanGilder, C., MacFarlane, G., Harrison, P., Lachenbruch, C., & Meyer, S., The Demographics of Suspected Deep Tissue Injury in the United States: An Analysis of the International Pressure Ulcer Prevalence Survey, Advances in Skin & Wound Care 23.6 at 254-61 (2010). Further, typically support surfaces do not protect the ankle/foot/heel from pressure ulcers at all times. For example, recumbent physiological changes, hemodynamics (decreased circulatory perfusion and venous congestion), and the anatomy (multiple bony prominences with minimal subcutaneous tissue attached to the legs which acts as a fulcrum) of the region may create unique and challenging needs that frequently exceeds the capabilities of a support surface to protect the ankle/foot/heel from mechanical stress injury. Further, support structures, particularly those addressing the ankle/foot/heel, may need to at least attempt to satisfy certain criteria such as, for example, elevate the heel (off of an adjacent surface), protect the sides of the foot and ankle, neutralize weight of lower extremity, maintain and promote circulation, address foot drop and lateral rotation of ankle, allow access to the foot for inspection/treatment, facilitate the musculoskeletal pump, minimize the risk for product contamination of surface or media, and/or be easy to clean. Additionally, such products may need to comply with regulatory requirements such as, for example, be flame retardant, biocompatible, and antimicrobial, as well as comply with FDA regulations and certain manufacturing processes such as, for example, ISO requirements. However, such support products may need to address a variety of other criteria, including, but not limited to, being lightweight, pliable yet durable, and being latex free.